The present invention relates to a hybrid drive system and also relates to a control device for a hybrid drive system.
It is previously known to arrange a hybrid drive system as a vehicle drive. For example DE-A-41 18 678 relates to a hybrid drive system which comprises an internal combustion engine, an electric battery and a drive shaft which can be driven by the internal combustion engine and the battery. The transmission of the energy from the internal combustion engine and the energy of the battery to the drive shaft is effected via a slip ring motor or an energy converter comprising two concentric rotors. The outer rotor, which is joined to the shaft of the internal combustion engine, is provided with permanent magnets and the inner rotor, which is joined to the drive shaft, is provided with windings which are supplied with alternating current with the aid of slip rings, and which are coupled via a current-converter to the battery. The drive shaft is joined to a transmission of a fixed gear ratio which distributes the rotory movement of the drive shaft to the wheel axles of the vehicle.
U.S. Pat. No. 3,796,278 relates to a control system for a hybrid drive system which, in one embodiment, comprises an internal combustion engine, a current source, an electromagnetic clutch, an electric motor and a gearbox. The internal combustion engine is coupled to the electric motor via the electromagnetic clutch. The output shaft of the electric motor is joined to the gearbox. The electromagnetic clutch is constructed of two concentric rotors, one of which is provided with a winding supplied with current from the current source. The hybrid drive system is controlled by control units which regulate the current supply to the electric motor.